英语语法分析

If the small-brained australopithecines were not toolmakers, what evolutionary advantage did they gain by walking upright?

如果脑子比较小的古猿不是工具制造者，那他们直立行走的进化优势是什么？

They found that its size was on a par with other australopithecines.

他们发现源泉种的脑尺寸与其它南猿一样。

They found that its size was on a par with other australopithecines, but its shape was more like that of a human brain.

他们发现源泉种的脑尺寸与其它南猿一样，但是其形状则更像人类的大脑。